KR20090108587A - Hydraulic two-circuit system and interconnecting valve arrangement - Google Patents

Abstract

A hydraulic two-circuit system (2, 4) for activating consumers (A1, B1; A2, B2; A3, B3) of a mobile unit, for example a track-laying unit, and an interconnecting valve arrangement (38), which is suitable for a two-circuit system (2, 4) of this type and via which the two circuits (2, 4) can be interconnected so as to add them together, are disclosed. According to the invention, the interconnecting valve arrangement has an interconnecting valve with two pressure connections (P1, P2), two LS input connections (LS1, LS2) and two LS output connections, wherein a valve body of the interconnecting valve is designed with four control surfaces, of which two control surfaces which act in one direction are acted upon by the highest load pressure (LS1) in the first circuit and by the pumping pressure (P2) in the second circuit, and the control surfaces acting in the other direction are acted upon by the highest load pressure (LS2) in the second circuit and by the pumping pressure (P1) in the first circuit.

Description

HYDRAULIC TWO-CIRCUIT SYSTEM AND INTERCONNECTING VALVE ARRANGEMENT}

The present invention relates to a hydraulic two-circuit system for controlling the consumer of a mobile device, in particular a crawler device, and an interconnecting valve device for the two-circuit system according to the preamble of claim 1.

In US 6,170,261 B1 a hydraulic two-circuit system of a moving device, for example a chain- or caterpillar device is known. In the case of this caterpillar device the body part comprises two chains which can each be controlled separately from one another by one of the hydraulic circuits. In addition, the two hydraulic circuits of the chain arrangement are connected to a rotating body and a part of the equipment, such as a boom, a stem and a shovel. Each of the two hydraulic circuits is supplied with a pressure medium by means of a regulating pump, which is each controlled in accordance with the maximum load pressure of the consumer in the circuit in which they are arranged.

If at least one consumer of the equipment in addition to the two chains is to be operated, two hydraulic circuits can be interconnected to prevent the pressure medium supply shortage. In the solution known from US 6,170,261 B1 the interconnection of two hydraulic circuits is made by an interconnecting valve, by means of the interconnecting valve the pressure lines connected with the two pumps are interconnected and the load pressure notification of the two circuits The lines are interconnected. The control of the interconnecting valve is made in accordance with the supply of pressure medium to the additional consumer. In addition, the user can connect the two circuits manually.

The disadvantage of this solution is that, for example, when controlling a consumer connected to one hydraulic circuit to a high pressure medium and a low pressure and a consumer connected to another circuit to a low pressure medium and a high pressure, the two circuits are connected via an interconnecting valve. Since it is connected, the higher load pressure of the second circuit is also applied in the first mentioned circuit. This higher load pressure causes the pump of the first circuit to run up, thereby raising the two circuits to a higher pressure level. Therefore, the pressure in the first hydraulic circuit must drop back to the required pressure level, which causes a significant energy loss. Another disadvantage is that the solution according to US Pat. No. 6,170,261 B1 requires considerable circuit technical effort for the pick-up of the load pressure from the additional consumer and for the control of the interconnecting valve.

In DE 102 545 738 A1 an improved two-circuit system is known, comprising an interconnecting valve arrangement with two manometers. Each one of the pressure gauges is assigned to one of the circuits, and the pressure gauge can control the connection with the other circuit according to the load pressure and the pump pressure in the one arranged circuit. The disadvantage in this solution is that the interconnecting valve arrangement has a relatively complex configuration.

It is an object of the present invention to provide a hydraulic two-circuit system and a simply constructed interconnecting valve arrangement suitable for the two-circuit system.

This object is achieved by a hydraulic two-circuit system having the features of claim 1 and an interconnecting valve arrangement having the features of claim 12.

 The interconnecting valve arrangement required for the summation of the pressure medium flow rates of the two-circuit system is formed substantially as an interconnecting valve arrangement comprising at least four control surfaces, the first circuit having two control surfaces acting in one direction. The maximum load pressure within and the pump pressure in the second circuit are applied, and the control surfaces acting in the other direction are applied with the maximum load pressure in the second circuit and the pump pressure in the first circuit. Depending on the control pressure difference that occurs, the two pressure connections for summation and the LS-input connection assigned to the first circuit are connected to the LS-output connection assigned to the second circuit, thereby reducing the pressure medium. If a higher load pressure acts on one of the circuits, while a higher pressure is needed, then the higher load pressure is prevented from being notified into another circuit that requires a lot of pressure medium and has a lower load pressure. Only the load pressures corresponding to the actual requirements within the two circuits are informed to the assigned arrangement of the regulating pumps, so that if a small pressure medium is required and a high pressure is applied to one of the circuits, the regulating pump of the circuit Is not run up, thereby significantly reducing energy loss compared to conventional solutions. In this solution, if a large pressure medium is required and a high pressure is applied to one of the circuits, the lower circuit is notified to the second circuit if a lower load pressure is applied to the second circuit.

In a preferred embodiment the valve body of the interconnecting valve is prestressed to the blocking position by the centering spring device.

Check valves are arranged in the load pressure lines to prevent higher load pressures from being communicated to other circuits when the interconnecting valve is opened.

According to an embodiment, the LS-line of one circuit is each connected with the LS-output connection of the interconnecting valve, which is assigned to the other circuit.

In a preferred embodiment, the control faces of the valve body to which the pump pressure and the load pressure are applied are embodied in the same size.

The interconnecting valve is simply such that the pump pressure and the load pressure of one circuit act on the back end faces that limit the spring space and the pump pressure and the load pressure of the other circuit simply act on the ring end faces of the valve body respectively. Is formed.

The valve body of the interconnecting valve includes an intermediate control collar in which two control edges are formed to control the connection between the two pressure connections. The valve body also includes two external LS-control collars each having one control edge formed to control the connection between the LS-input connection of one circuit and the LS-output connection of the other circuit. The spring space side back faces of the two control collars form the back end faces described above.

Preferably, between the intermediate control collar and the LS-control collar, different collars, each of which the above-mentioned ring-shaped end faces are arranged, are formed.

This configuration allows for symmetrical formation of the valve body, making the manufacture and assembly of the valve body particularly simple.

The construction of the interconnecting valve is simpler if the aforementioned check valves are integrated into the valve housing of the interconnecting valve.

Another preferred embodiment of the invention is the subject of the other claims.

Preferred embodiments of the invention are explained in more detail below with reference to the drawings.

1 is a circuit diagram of a control block for controlling a crawler,

2 is a circuit diagram of the interconnecting valve arrangement of the two- or multi-circuit system of FIG.

3 is a specific embodiment of the interconnecting valve arrangement of FIG. 1.

1 shows a circuit diagram of a hydraulic excavator control unit 1. The excavator control is designed as a two-circuit system comprising two hydraulic circuits 2 and 4, each of which is supplied with a pressure medium by means of a control pump, not shown. The excavator provided with the control part shown in FIG. 1 has a body part with two chains, and the drivers of the chains can be supplied with the pressure medium independently of each other by the two circuits 2, 4. In addition to the actuator, the two-circuit system also controls other consumers of the excavator, such as a rotor, stem, shovel or boom.

The control block implementing the excavator control according to FIG. 1 is of plate type, and two control pumps, not shown, are connected to the pressure connections P1 and P2 of the control block. The control block also comprises a tank connection T and actuation connections A1, B1 and A2, B2, to which actuators of the right or left chain are connected. Other connections (A3, B3 and A4, A4, etc.) are connected to other consumers of the excavator, such as actuators of the rotor and hydraulic cylinders for the operation of the stem, shovel or boom. In the illustrated embodiment, the booms are connected to the connectors A2 and B2 and the shovels are connected to the connectors A4 and B4.

In addition, the illustrated control block includes two load pressure connections LS1 and LS2, through which the load pressure acting on each circuit 2 and 4 is picked up, and the output flow control valve of the regulating pump is picked up. Guided (not shown), the regulating pump is controlled according to the maximum load pressure.

The control of the consumer described above is achieved by a proportional controllable directional valve 6, and a pressure gauge 8 is arranged behind the directional valve 6. The direction valve 6 comprises a speed portion and a direction portion forming a variable measurement orifice, the measurement orifice is arranged before the pressure gauge 8 and the direction portion is disposed after the pressure gauge 8 when viewed in the flow direction. Each pressure gauge 8 receives the load pressure in the closing direction and the pressure after the measuring orifice of the directional valve 6 when viewed in the flow direction in the opening direction. Since the pressure gauge piston is adjusted to an adjustment position in which the pressure drop is kept constant by the measuring orifice of the proportionally adjustable directional valve 6 in accordance with the applied control pressure, flow rate control is independent of the load pressure. Since this LS-control part is already known, a detailed description of the configuration of the directional valve 6 and the subsequently disposed pressure gauge 8 is omitted. Control of the directional valve 6 is effected respectively by a pilot valve, through which a control pressure is applied to the end side control surfaces of the slide of the directional valve 6. The pilot valve is operated according to the operation of the joystick, for example.

The connections of the directional valves 6 are connected with the pressure connection P1 or P2 via the pressure line 14. Each directional valve also comprises two actuating connections, which are connected to the consumer connections A, B which are assigned and arranged via actuating lines 18 or 20, respectively. The output connection of the directional valve 6 is connected with the tank connection T of the control block via the tank line 22 to guide the return of the pressure medium from the consumer.

In addition, pressure limiting valves are also provided in the operating lines, respectively, to limit the maximum pressure directed to the consumer, and pressure limiting valves limiting the pressure at the operating connections A2, B2, B1, B3, and A4 not shown. They perform a suction function later, so that in the prior operation of the consumer (negative load), the pressure medium can be sucked in later from the tank, thus preventing cavitation. Load pressure notification lines 28, 30 connected to the load pressure connections of the two circuits 2, 4, respectively, are connected with the common tank line 22 via the LS-flow control valve 32 or 34.

The pressure gauge 8 informs the load pressure line 28 or 30 of the pressure applied to the input portion (pressure after the measurement orifice in the flow direction) at the fully controlled final position, so that each circuit in the load pressure line It is implemented such that the maximum load pressure in (2, 4) is always given.

The above-mentioned directional valves, including the assigned pressure gauge 8, the pilot valves 10, 12 and the pressure limiting valves 24, 25, can each be accommodated in a disc or common control block. For the connection of the two hydraulic circuits 2, 4, an interconnecting valve arrangement 38 is provided in the intermediate disk 36, by means of the interconnecting valve arrangement two hydraulic circuits 2 in a specific operating state. Since the pressure lines 14, 16 of 4 can be interconnected, the controlled consumers are commonly supplied with a pressure medium by two regulating pumps.

The construction of the interconnecting valve arrangement is described below with reference to FIGS. 2 and 3.

According to the circuit diagram of the interconnecting valve device of FIG. 2, the interconnecting valve device comprises an interconnecting valve 40 designed as a pressure gauge, the pressure gauge slide of the interconnecting valve being referred to as valve body 42 in the following. Two control surfaces A1, A2 comprising two control surfaces A1, A2, A3 and A4, which act in one direction, are subjected to the pump pressure of the second circuit and the load pressure of the first circuit and to the other direction The control surfaces A3 and A4 acting as the pump pressure of the first circuit and the load pressure of the second circuit are applied. Accordingly, the control surface A1 is connected to the pressure line 16 of the second circuit 4 via the pressure control line 44, and the control surface A2 acting in the same direction is the LS control line 46. Is connected to the load pressure notification line 28 of the first circuit. Control surfaces A3 and A4 acting in the opposite direction are connected to the pressure line 14 via another pressure control line 48 or via the other LS control line 50 to inform the load pressure of the second circuit. Is connected to the line 30. The control surfaces A1, A2, A3, A4 are each identical.

The valve body 42 is prestressed by the centering spring device 51 to the central shut off position, in which position two pressure connections P1 and P2 are connected to the pressure lines 14, 16, the first circuit. The two connection parts LS1 and LS1 'allocated and allocated to (2) and the two connection parts LS2 and LS2' allocated and allocated to the second circuit 4 are blocked.

The LS-input connection LS1 is connected with the load pressure notification line 28 of the first circuit 2 through the LS-channel 52 and through the check valve 54 opened in the direction of the connection LS1, In the load pressure notification line 28, the LS-output connection LS1 'is also connected through the LS-branch channel 56. The load pressure notification line 30 of the second circuit 4 is thus connected to the LS-input connection LS2 via another LS-channel 58 and another check valve 60 and the other LS-channel 62. It is connected to the LS-output connection LS2 '. Depending on the control pressure difference applied, the valve body 42 of the interconnecting valve 40 moves to the adjustment position indicated at the top (see FIG. 2), i.e. do. In regulating positions a and b, the amount of pressure medium flow combined from one circuit with a higher pressure level to another is throttled through the sequence valve 40 to a lower pressure level. If the pressure difference between the pump pressure and the load pressure in the first circuit is equal to the pressure difference between the pump pressure and the load pressure in the second circuit, the adjustment position is set. Within the regulating positions a, the pressure medium of the second circuit 4 is added to the pressure medium flow rate of the first circuit 2, and the LS-connections LS1 and LS2 ′ are also connected to each other, but the two The other LS-connectors LS2, LS1 'are isolated relative to each other. When the load pressure in the first circuit 2 is lower, the check valve 54 prevents the higher load pressure of the second circuit 4 from being notified into the first circuit, so that the adjustment assigned to the first circuit is arranged. The pump will not run up in this case. If a higher load pressure is applied in the first circuit 2, this is notified to the regulating pump of the second circuit via the open check valve 54 and the two connected LS-connections LS1 and LS2 ′ and accordingly The regulating pump is running up.

The pressure connections P1 and P2 are thus connected to each other when moving to one of the regulating positions b, so that the pressure medium of the first circuit is added to the pressure medium flow rate of the second circuit and the LS-connections LS2 and LS1 'are connected to each other, and the check valve 60 has a lower load pressure (in the load pressure notification line 28) in the first circuit 2, so that the load pressure notification line 30 of the second circuit 4 is reduced. To be notified).

3 shows a specific embodiment of the interconnecting valve arrangement 38 according to FIG. 2.

As mentioned above, the interconnecting valve arrangement may be integrated into the intermediate disk 36 of the control block or mounted on the control block as a unique valve. 3 is a longitudinal cross-sectional view of the valve housing 36 housing the valve disc 36 or the interconnecting valve arrangement 38. A valve bore 64 is formed in the valve disc 36, in which a pressure gauge slide or valve body 42 is axially guided. The valve bore 64 extends to two pressure chambers 66, 68 in the middle region, which are separated from each other by the housing strip 70. The pressure chamber 66 is connected with the pressure connection P1 and the pressure chamber 68 is connected with the pressure connection P2. In the direction of the end of the valve bore, the valve bore extends radially into the LS-ring spaces 70, 72 and 74, 76, respectively, and the outer ring spaces 70, 76 extend with the load pressure notification channel 30. Connected, whereby the maximum load pressure of the second circuit 4 is applied in the spaces. The two inner ring spaces 72, 74 are connected to the load pressure notification line 28, thereby applying the maximum load pressure of the first circuit 2. 3 shows load pressure notification lines 28, an LS-channel 52 extending into the ring space 72, a check valve 54 lying within the LS-channel and an LS extending into the ring space 74. Branch channel 56 is shown. The connection of the load pressure notification line 30 and the two other ring-shaped spaces 70, 76 is made by corresponding channels in which the check valve 60 is integrated (not shown in FIG. 3).

The valve body 42 includes an intermediate control collar 78 with two control edges 80, 82 formed with fine control notches. Upon axial displacement of the valve body 42, the connection between the two pressure chambers 66, 68 is controlled by one of the control edges 80, 82, the pressure chambers-as described above-of the pressure line. To 14 or 16, respectively. In FIG. 2, the pressure chamber 66 is connected to the connecting portion P1, and the pressure chamber 68 is connected to the connecting portion P2. For convenience, the drawing numbers of the connections in FIG. 3 are indicated in parentheses.

The valve body 42 includes two collars 84, 86 on both sides at an axial distance from the intermediate control collar 78, the collars being external through a radially reduced piston neck, respectively. It is connected to a control collar 88 or 90 placed on it. Each control collar 88, 90 is guided in a reduction sleeve 92 or 94, which sleeve is inserted into a stepped enlarged end portion on the end side of the valve bore 64, thereby providing a valve body 42. Reduce the effective guide diameter and form the difference between the faces. The end faces of the collars 84 and 86, facing the control collars 88 and 90, are provided with one ring end face each forming the control faces 42 or 43.

The control surface A3, together with the adjacent end faces of the reducing bush 92, limits the space 96 in which the pressure of the pressure line 14 and the pressure of the pressure connection P1 are applied. The ring-shaped end face A2 of the collar 86 together with the adjacent end face of the shrinking bush 94 limits the pressure in the pressure line 16 and other spaces 98 where pressure at the pressure connection P2 is applied. . The two outer control collars 88, 90 are slightly reduced in the middle by the piston necks 100, 102, so that one control edge 104, 106 is formed, respectively. The connection between the ring spaces 72 and 70 is controlled by the control edge 104 lying on the left side of FIG. 3, and the connection between the ring spaces 74 and 76 is controlled by the right control edge 106. In the basic position shown of the valve body 42, the connection is interrupted by the control edges 104, 106.

The two end faces of the valve body 42 form control surfaces A1 and A1 (see FIG. 2), which control surfaces are subjected to pressure in the pressure line 16 of the second circuit or of the second circuit. Maximum load pressure is applied.

In the illustrated embodiment the end faces A1 and A4 or the ring end faces A2 and A3 are each embodied in the same plane.

As mentioned in FIG. 2, the valve body 42 is prestressed to an intermediate position shown by the centering spring device 51. The centering spring device 51 also acts as an adjustment spring device and is embodied with two adjustment springs 108, 109 in a specific embodiment, wherein the spring constant of the springs is set smaller than the pump-ΔP. When the pump-ΔP is 20 bar, the spring force of the regulating springs 108, 110 is about delta-P-difference: 3 to 6 bar (detected in the experiment).

Two regulating springs 108, 110 are respectively supported on spring bushes 112, 114 screwed into the valve bore 64, and end faces of the valve body 42 by spring plates 116, 118. It is fixed to A1 and A4, respectively. The radially extending ring-shaped end faces of the reducing bushes 92, 94, facing the adjustment springs 108, 110 are used as stops for the spring plates 116, 118. These two stops also determine the shown intermediate position of the valve body 42.

To help understand the function, the operation of the excavator control is described below.

The consumer, for example the stem, which is connected to the operative connections A2, B2, requires a lot of pressure medium, so that a relatively low pump pressure is applied in the hydraulic circuit 2. In contrast, a consumer, for example a boom, which is connected to the operating connections A4 and B4 of the second circuit, requires only a small amount of pressure medium at a relatively high pump pressure. Due to the pressure drop in the first circuit 2 (low pressure in the pressure line 14), the valve body 86 is moved to the left in FIG. 3 against the force of the regulating spring 108, so that the pressure chambers 86, Since the pressure medium flow path between the 88 is controlled by the fine control notch of the control edge 80, the pressure medium of the second circuit 4 is combined with the first circuit 1 (from P1 of the interconnecting valve 40). Pressure medium flow to P2). In parallel with this, the connection between the two LS-ring spaces 70, 72 is controlled by the control edge 104, so that the connection between the LS-input connection LS1 and the LS-output connection LS2 ′ is opened. . By the check valve 54, higher load pressure in the second circuit 4 is prevented from being notified into the first circuit 2 which receives the pressure medium of the second circuit. The interconnecting valve 40 operating on the principle of the manometer is adjusted to the regulating position, so that the pressure medium supplied by the regulating pump of the second circuit 4 is throttled to the pressure level of the first circuit 2 and both circuits The pressure difference at (pump pressure-load pressure) is about the same.

The energy savings in this case are calculated as follows:

P stem = 60 bar Q stem = 300 ℓ / min

P boom = 140 bar Q boom = 100 ℓ / min

2-circuit: Q pump 1 = Q pump 2 = 200 ℓ / min

1-circuit: QP (1-circuit) = 400 ℓ / min

Energy saving of the above embodiment: 28.6%

  [1/600 is l / min × bar conversion factor (kW)]

When the first circuit 2 is combined with the second circuit 4, the valve body 42 moves to the right in FIG. 3, so that the control edge 82 connects the pressure chamber 66 to the pressure chamber 68. And the pressure medium flow path from the pressure connection P1 to the pressure connection P2 is controlled. At the same time the connection between the two LS-ringed spaces 74, 76 is controlled by the control edge 106, and the higher load pressure in the circuit 4 which receives the pressure medium is the regulating pump of the first circuit 2. The regulating pump is run up upon notification. If the load pressure in the second circuit 4 should be lower, the check valve 60 prevents the higher load pressure from being notified into the circuit.

The solution according to the invention is characterized by a very compact configuration that can be achieved with little device technical effort.

The present invention relates to a hydraulic two-circuit system for the control of consumers of a mobile device, such as a caterpillar device, and an interconnecting valve device suitable for such a two-circuit system. Circuits may be connected to each other for summation. According to the invention, the interconnecting valve arrangement comprises an interconnecting valve having two pressure connections, two LS-input connections and two LS-output connections, wherein the valve body of the interconnecting valve has four controls. Two control surfaces comprising surfaces, acting in one direction of the control surfaces, are subjected to a maximum load pressure in a first circuit and a pump pressure in a second circuit, and the control surfaces acting in a different direction the second circuit The maximum load pressure in and the pump pressure in the first circuit are applied.

Claims (12)

A hydraulic two-circuit system for the control of consumers of a mobile device, in particular a crawler device, in which each of the hydraulic circuits 2, 4 is assigned an assignment pump, through which the pressure medium is assigned to the consumer. Two circuits may be supplied via an interconnecting valve arrangement 38 such that the regulating pump of one of the two circuits 2, 4 sends the pressure medium to the other circuit 4, 2. In a hydraulic two-circuit system, the regulating pumps can be connected to each other, and the regulating pumps can be respectively controlled in accordance with the load pressure in the assigned and arranged circuit of the two circuits 2, 4. The interconnecting valve arrangement 38 is interconnected with two pressure connections P1, P2, two LS-input connections, two LS-output connections LS1, LS2; LS1 ', LS2'. A valve 40 and a valve body 42, the valve body being subjected to a maximum load pressure in the first circuit 2 and a pump pressure in the second circuit 4 in one direction and in the other direction. Since the maximum load pressure in the second circuit (4) and the pump pressure in the first circuit (2) is applied, according to the control pressure difference acting on the valve body 42, the two pressure connections (P1, P2), and the two LS-outputs in which one of the two LS-input connections LS1 and LS2 allocated to one of the two circuits is allocated to the other circuit. Hydraulic two-circuit characterized in that it can be connected to one LS-output connection of one of the connections (LS1 ', LS2') system. The method of claim 1, Hydraulic valve system, characterized in that the valve body (42) is prestressed to the blocking position by the centering spring device (51). The method according to claim 1 or 2, A hydraulic two-circuit system, characterized in that check valves (54, 60) are opened in the LS-lines (52, 62) extending to the LS-input connections (LS1, LS2), respectively. The method of claim 3, wherein The LS-lines 52, 62 of one of the two circuits 2, 4 are connected to LS-output connections LS1 ′, LS2 ′, which are allocated to the other circuits 2, 4, respectively. Hydraulic two-circuit system, characterized in that. The method according to any one of claims 1 to 4, Hydraulic two-circuit system, characterized in that the control surfaces (A1, A2, A3, A4) to which the pump pressures and the load pressures are applied are the same magnitude. The method of claim 5, wherein The pump pressure and the load pressure of one of the two circuits act on the rear end surfaces A1 and A4 which limit the spring space, and the pump pressure and the load pressure of the other circuit 4 depend on the valve. A hydraulic two-circuit system, each acting on ring-shaped end faces A2 and A3 of the body 86. The method of claim 6, An intermediate control collar 78 in which two control edges 80, 82 are formed for controlling the connection between the two pressure connections P1, P2, and one of the two circuits 2, 4 One control edge 104, 106 is formed respectively to control the connection of the LS-input connections LS1, LS2 of the circuits of the circuit and the LS-output connections LS1 ', LS2' of the other circuits 2, 4 of And two outer LS-control collars (88, 90), wherein the spring space side backs of the control collars form end faces (A1, A4). The method of claim 7, wherein Collars 84 and 86 are formed between the control collar 78 and the LS-control collars 90 and 92, respectively, and the ring-shaped end faces A2 and A3 are provided on the collars 84 and 86, respectively. Hydraulic two-circuit system characterized by. The method according to claim 7 or 8, Hydraulic valve system, characterized in that the valve body (42) is formed symmetrically with respect to the intermediate control collar (78). The method of claim 1, wherein The check valves (54, 60) are arranged in a valve housing of the interconnecting valve (40). The method according to any one of the preceding claims, The centering spring arrangement (51) comprises regulating springs (108, 110), wherein the pressure of the regulating springs is slightly lower than the pump-ΔP. Interconnecting valve with two pressure connections P1, P2, two LS-input connections, two LS-output connections LS1, LS2; LS1 ', LS2', and a valve body 42 An interconnecting valve arrangement for a hydraulic two-circuit system comprising 40, The valve body is subjected to the maximum load pressure in the first circuit 2 and the pump pressure in the second circuit 4 in one direction, and the maximum load pressure in the second circuit 4 and in the other direction. The pump pressure in the first circuit 2 is applied, thereby depending on the difference in the control pressure acting on the valve body 42, the two pressure connections P1, P2, and one of the two circuits. One of the two LS-input connections LS1, LS2 'assigned to one of the two LS-input connections LS1, LS2 assigned to the other circuit Interconnecting valve arrangement for a hydraulic two-circuit system, characterized in that it can be connected to the LS-output connection of the.

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